Uber has a new short-term car leasing partner for its drivers, and it’s none other than General Motors—a major investor in rival ride-hailing company Lyft.

On Tuesday, Uber and a 10-month-old car-sharing division within GM announced a new pilot program in San Francisco that will let Uber drivers rent cars by the week for both work and personal use. As part of the 90 day test, drivers will be able to rent cars for $179 weekly (plus taxes and fees) including unlimited miles and insurance.

Uber drivers will be able to choose between Chevrolet Cruze, Malibu, and Trax vehicles.

This new car rental option is only the latest in Uber’s range of leasing and rental programs since the company first started offering them to drivers in 2013. In the past year, Uber has also teamed up with Enterprise and Hertz to provide short-term car rentals.

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General Motors debuted its car sharing program, Maven, in January as an alternative to car ownership for its customers. Maven’s various programs include car rentals for city dwellers and peer-to-peer car-sharing. Maven is now available in 10 U.S. cities, and customers have driven more than 23 million miles with those vehicles, according to the company.

General Motors is also a car provider for Lyft’s Express Drive car rental program, along with Hertz. Like the car rental test with Uber, the Express Drive program lets Lyft drivers rent cars.

GM’s ties to Lyft are deep. In January, it invested $500 million in Lyft, and the two companies are working on autonomous driving technology as the auto industry races to put self-driving cars on the road.

GM’s partnership with Uber raises questions about its existing relationship with Lyft. Does it mean that GM is shifting its allegiance?

Of course not, say the three companies.

“Similar to how we work with Hertz and Maven on Express Drive, it’s expected that vehicle access programs have multiple partners,” a Lyft spokeswoman told Fortune. She added that these programs are unrelated to Lyft’s work with GM on autonomous driving, which she described as being at the center of the companies’ relationship.

A GM spokeswoman declined to comment on whether the company’s investment contract with Lyft precludes it from working with Uber. But the spokeswoman said that the latest pilot with Uber is unrelated to its investment in Uber’s rival, and that just like with any other partnership, it will protect its partner’s data from other parties.

“The pilot with Uber is a commercial undertaking of GM’s personal mobility brand Maven to provide Uber driver-partners with flexible options to access vehicles,” said the spokeswoman.

An Uber spokesman also dismissed concerns about any conflicts of interest involved in partnering with both Uber and Lyft. He acknowledged that GM is heavily involved with Lyft while adding that Uber has been working with several car manufacturers over the years.

Uber has already been working with GM to provide discounts on cars to its drivers through Uber’s Vehicle Solutions team for some time.

An earlier version incorrectly stated that Uber has been working with GM through its Xchange Leasing program. The story has been updated.